Pakistan's home ministry says it is not immediately lifting a travel ban on former military ruler Pervez Musharraf, who suffered a heart problem on the way to his treason trial a few days ago.

The 70-year-old former ruler was taken ill and rushed to a military hospital on Thursday as he was being transported under heavy guard to hear treason charges against him at a special tribunal in Islamabad.

The former army chief was Saturday spending his third day at the Armed Forces Institute of Cardiology in Rawalpindi, the garrison city bordering Islamabad.

His lawyer Ahmed Raza Kasuri said doctors were monitoring his condition in the intensive care unit.

The sudden health scare was met with scepticism from some observers and feverish media speculation that his departure from Pakistan on medical grounds could be imminent.

But Musharaf's name has been put on an official "Exit Control List" (ECL) to bar him from travelling abroad, and a court in the Southern Sindh province ruled last month against lifting the ban.

"There is no intention to allow him overseas travel at the moment," a senior official of the ministry of interior told AFP.

He denied reports that Musharraf's wife Sehba has filed an application with the ministry seeking to lift the ban.

"No fresh application has been filed by Madam Sehba, and it is clear that the travel ban on Musharraf is not being lifted.

He won't be allowed to travel abroad immediately," the official said.

Musharraf's lawyer Kasuri told AFP earlier on Saturday that the doctors have sent his medical reports to experts in Britain, who will determine his further treatment.

"The reports of the medical tests of General (retired) Musharraf have been sent to the experts for further examination in the UK," Kasuri told AFP.

"The decision about his further treatment to be carried out in Pakistan or abroad will be taken in the light of the British experts' opinion," he said.

"Of course they (the Pakistan doctors) will give him excellent treatment, he is a former President of Pakistan and Army Chief, he is a high profile personality," Kasuri said.

There has been speculation for months that Musharraf would be spirited out of the country before facing the courts in order to head off a potentially destabilising clash between the government and the all-powerful military.

Ministers have repeatedly said they will not lift the ban.

Kasuri had said on Friday that Musharraf's legal team was expected to receive a report on his condition before the next court hearing on Monday.

Musharraf's team says the treason allegations, which relate to his imposition of emergency rule in November 2007, are politically motivated and his lawyers have challenged the authority of the three-judge tribunal.

Aside from the treason allegations, Musharraf also faces trial over the assassination of former prime minister Benazir Bhutto, the death of a rebel leader, a deadly raid on a radical mosque and the detention of judges.

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